1. Field of the Invention
The present invention relates to an apparatus for cutting fiber, which is situated, for instance, at the back of the nip roller of a crimping machine and which is designed to cut a fiber bundle crimped by a crimping machine to various lengths.
2. Description of the Prior Art
Among conventional cutting apparatus of this kind, there is an outer track type of cutting apparatus, for example, as disclosed in the published Examined Japanese Patent Application Sho. 59(1984)-27405, Unexamined Japanese Patent Application Sho. 56(1981)-73118, Unexamined Japanese Patent Application Sho. 56(1981)-73119 and Unexamined Japanese Patent Application Sho. 57(1982)-95314. In this type of apparatus, a cutting blade is provided on the circumference of a rotary disk, and a fiber bundle is wound around the disk and is cut to lengths corresponding to the interval of blades under pressure created by a pressure roll provided outside of the disk.
There are also some different types of known fiber cutting apparatus. One of these is an inner track type as disclosed, for example, in the published Unexamined Japanese Patent Application Sho. 50(1975)-116723. In this apparatus cutting blades are provided in a circle with their edges directed inward and the fiber bundle is cut between these blades under pressure created by a pressure roller provided outside of the circle. There is also an inner and outer combined track type of cutting apparatus which combines a disk having cutting blades on its circumference and a ring having cutting blades on its inner surface and wherein the fiber bundle is cut between the two pairs of blades.
Cutting apparatus of the conventional types are all designed to cut the fiber bundle at a location between the blades arranged in a circle. Accordingly, a slackening of the fiber bundle between the blades or the production of flock due to the shaving of the bundle by the blades during the movement of the fiber bundle cannot be prevented. Further, in the case of a high speed crimping apparatus having a nip acceleration speed of 6,000 m per minute, as disclosed in Unexamined Patent Application Hei. 1(1989)-201540, the fiber bundle could not be cut accurately.